Come on @Gammalite you've hunted your horse out of the gate to get the lead, the momentum over the first 200m sees you out by a few lengths and YOU want to pull up on the reins! You better than anyone knows the risk of that. The horse is bowling along relaxed on the bit and doing roughly 30.5 second sectionals. Why hand up the momentum advantage you got?
But every other horse ran a faster 400m at some stage during the race. So you expect Cox to be looking around to see how far out in front he is? You know that can unbalance a horse. The horse was on the bit, not on a loose rein and the whip not shown. You see this all the time in Ozzie races.
All said and done it did go a bit quick for the first half but not by much.